nutUWallFunctionFvPatchScalarField.C

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#include "nutUWallFunctionFvPatchScalarField.H"
#include "turbulenceModel.H"
#include "fvPatchFieldMapper.H"
#include "volFields.H"
#include "addToRunTimeSelectionTable.H"


// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //

Foam::tmp<Foam::scalarField>
Foam::nutUWallFunctionFvPatchScalarField::calcNut() const
{
    const label patchi = patch().index();

    const auto& turbModel = db().lookupObject<turbulenceModel>
    (
        IOobject::groupName
        (
            turbulenceModel::propertiesName,
            internalField().group()
        )
    );

    const fvPatchVectorField& Uw = U(turbModel).boundaryField()[patchi];
    const scalarField magUp(mag(Uw.patchInternalField() - Uw));

    const tmp<scalarField> tnuw = turbModel.nu(patchi);
    const scalarField& nuw = tnuw();

    const scalar kappa = wallCoeffs_.kappa();
    const scalar E = wallCoeffs_.E();
    const scalar yPlusLam = wallCoeffs_.yPlusLam();

    tmp<scalarField> tyPlus = calcYPlus(magUp);
    const scalarField& yPlus = tyPlus();

    auto tnutw = tmp<scalarField>::New(patch().size(), Zero);
    auto& nutw = tnutw.ref();

    forAll(yPlus, facei)
    {
        // Viscous sublayer contribution
        const scalar nutVis = 0;

        // Inertial sublayer contribution
        const scalar nutLog =
            nuw[facei]
           *(yPlus[facei]*kappa/log(max(E*yPlus[facei], 1 + 1e-4)) - 1.0);

        switch (blender_)
        {
            case blenderType::STEPWISE:
            {
                if (yPlus[facei] > yPlusLam)
                {
                    nutw[facei] = nutLog;
                }
                else
                {
                    nutw[facei] = nutVis;
                }
                break;
            }

            case blenderType::MAX:
            {
                // (PH:Eq. 27)
                nutw[facei] = max(nutVis, nutLog);
                break;
            }

            case blenderType::BINOMIAL:
            {
                // (ME:Eqs. 15-16)
                nutw[facei] =
                    pow
                    (
                        pow(nutVis, n_) + pow(nutLog, n_),
                        scalar(1)/n_
                    );
                break;
            }

            case blenderType::EXPONENTIAL:
            {
                // (PH:Eq. 31)
                const scalar Gamma =
                    0.01*pow4(yPlus[facei])/(1 + 5*yPlus[facei]);
                const scalar invGamma = scalar(1)/(Gamma + ROOTVSMALL);

                nutw[facei] = nutVis*exp(-Gamma) + nutLog*exp(-invGamma);
                break;
            }

            case blenderType::TANH:
            {
                // (KAS:Eqs. 33-34)
                const scalar phiTanh = tanh(pow4(0.1*yPlus[facei]));
                const scalar b1 = nutVis + nutLog;
                const scalar b2 =
                    pow(pow(nutVis, 1.2) + pow(nutLog, 1.2), 1.0/1.2);

                nutw[facei] = phiTanh*b1 + (1 - phiTanh)*b2;
                break;
            }
        }
    }

    return tnutw;
}


Foam::tmp<Foam::scalarField>
Foam::nutUWallFunctionFvPatchScalarField::calcYPlus
(
    const scalarField& magUp
) const
{
    const label patchi = patch().index();

    const auto& turbModel = db().lookupObject<turbulenceModel>
    (
        IOobject::groupName
        (
            turbulenceModel::propertiesName,
            internalField().group()
        )
    );

    const scalarField& y = turbModel.y()[patchi];

    const tmp<scalarField> tnuw = turbModel.nu(patchi);
    const scalarField& nuw = tnuw();

    const scalar kappa = wallCoeffs_.kappa();
    const scalar E = wallCoeffs_.E();
    const scalar yPlusLam = wallCoeffs_.yPlusLam();

    auto tyPlus = tmp<scalarField>::New(patch().size(), Zero);
    auto& yPlus = tyPlus.ref();

    forAll(yPlus, facei)
    {
        const scalar kappaRe = kappa*magUp[facei]*y[facei]/nuw[facei];

        scalar yp = yPlusLam;
        const scalar ryPlusLam = 1.0/yp;

        int iter = 0;
        scalar yPlusLast = 0.0;

        do
        {
            yPlusLast = yp;
            yp = (kappaRe + yp)/(1.0 + log(E*yp));

        } while (mag(ryPlusLam*(yp - yPlusLast)) > 0.01 && ++iter < 10 );

        yPlus[facei] = max(scalar(0), yp);
    }

    return tyPlus;
}


void Foam::nutUWallFunctionFvPatchScalarField::writeLocalEntries
(
    Ostream& os
) const
{
    wallFunctionBlenders::writeEntries(os);
}


// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //

Foam::nutUWallFunctionFvPatchScalarField::nutUWallFunctionFvPatchScalarField
(
    const fvPatch& p,
    const DimensionedField<scalar, volMesh>& iF
)
:
    nutWallFunctionFvPatchScalarField(p, iF),
    wallFunctionBlenders()
{}


Foam::nutUWallFunctionFvPatchScalarField::nutUWallFunctionFvPatchScalarField
(
    const nutUWallFunctionFvPatchScalarField& ptf,
    const fvPatch& p,
    const DimensionedField<scalar, volMesh>& iF,
    const fvPatchFieldMapper& mapper
)
:
    nutWallFunctionFvPatchScalarField(ptf, p, iF, mapper),
    wallFunctionBlenders(ptf)
{}


Foam::nutUWallFunctionFvPatchScalarField::nutUWallFunctionFvPatchScalarField
(
    const fvPatch& p,
    const DimensionedField<scalar, volMesh>& iF,
    const dictionary& dict
)
:
    nutWallFunctionFvPatchScalarField(p, iF, dict),
    wallFunctionBlenders(dict, blenderType::STEPWISE, scalar(4))
{}


Foam::nutUWallFunctionFvPatchScalarField::nutUWallFunctionFvPatchScalarField
(
    const nutUWallFunctionFvPatchScalarField& sawfpsf
)
:
    nutWallFunctionFvPatchScalarField(sawfpsf),
    wallFunctionBlenders(sawfpsf)
{}


Foam::nutUWallFunctionFvPatchScalarField::nutUWallFunctionFvPatchScalarField
(
    const nutUWallFunctionFvPatchScalarField& sawfpsf,
    const DimensionedField<scalar, volMesh>& iF
)
:
    nutWallFunctionFvPatchScalarField(sawfpsf, iF),
    wallFunctionBlenders(sawfpsf)
{}


// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

Foam::tmp<Foam::scalarField>
Foam::nutUWallFunctionFvPatchScalarField::yPlus() const
{
    const label patchi = patch().index();

    const auto& turbModel = db().lookupObject<turbulenceModel>
    (
        IOobject::groupName
        (
            turbulenceModel::propertiesName,
            internalField().group()
        )
    );

    const scalarField& y = turbModel.y()[patchi];

    tmp<scalarField> tnuw = turbModel.nu(patchi);
    const scalarField& nuw = tnuw();

    tmp<scalarField> tnuEff = turbModel.nuEff(patchi);
    const scalarField& nuEff = tnuEff();

    const fvPatchVectorField& Uw = U(turbModel).boundaryField()[patchi];
    const scalarField magUp(mag(Uw.patchInternalField() - Uw));
    const scalarField magGradUw(mag(Uw.snGrad()));

    const scalar yPlusLam = wallCoeffs_.yPlusLam();

    tmp<scalarField> tyPlus = calcYPlus(magUp);
    scalarField& yPlus = tyPlus.ref();

    forAll(yPlus, facei)
    {
        if (yPlusLam > yPlus[facei])
        {
            // viscous sublayer
            yPlus[facei] =
                y[facei]*sqrt(nuEff[facei]*magGradUw[facei])/nuw[facei];
        }
    }

    return tyPlus;
}


void Foam::nutUWallFunctionFvPatchScalarField::write
(
    Ostream& os
) const
{
    nutWallFunctionFvPatchScalarField::write(os);
    writeLocalEntries(os);
    writeEntry("value", os);
}


// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

namespace Foam
{
    makePatchTypeField
    (
        fvPatchScalarField,
        nutUWallFunctionFvPatchScalarField
    );
}


// ************************************************************************* //